Process of manufacturing decolorizing and clarifying material.



UNITED STATES Patented May 26, 1903.

PATENT OFFICE.

ROBERT LEONARD JENKS, OF LONDON, ENGLAND, ASSIGNOR TO GEORGE ARCHIBALD OLOWES, OF LONDON, AND ERNEST PAUL HATSCHEK, OF NEEDHAM MARKET, ENGLAND.

PROCESS OF MANUFACTURING DECOLORI ZING AND CLARIFYING MATERIAL.

SPECIFICATION forming part of Letters Patent No. 729,350, dated May 26, 1903.

Application filed November 22, 1902;

To all whom it may concern:

Beitknownthat 1, ROBERT LEONARD J ENKS, a subject of the King of Great Britain, residing at London, England, have invented a new and useful Process of Manufacturing Decolorizing and Clarifying Material, of which the following is a full, clear,- and exact description.

This invention relates to a process for manufacturing materials to be used for decolorizing and clarifying tanning extracts and other liquids. At present this result is generally accomplished by the addition of coagulable albumen, which may or may not precipitate one or other of the constituents of the liquid under treatment. In either case the albumen is again separated as a coagulum by heating the liquid to the-required degree of temperature. During coagulation or in settling an uncertain amount of coloring-matter is removed. Such a treatment is adopted, for example, with tannin extracts which are decolorized by albumen from various sources. This, however, precipitates an appreciable quantity of tannin and retains it when coagulated, so that the processof removing color entails a considerable-loss of tannin, a loss which is minimized by the use of my material. This material is a practically non-coag nlable substance, nearly neutral to tannic acid, and consists of dead yeastcells the contents of which have been largely removed by any suitable process; but by the treatment hereinafter described the yeast-cellsbehave efficiently as a decolorizing agent.

Any suitable yeast is mixed with water to a suitable consistence, and is then heated to and kept at a temperature of about centigrade,preferably in oacuo, for severalhours, so as to kill the yeast and to remove any gum and other soluble matter adhering to the cells. The liquid thus obtained is run off, and the residue of dead yeast-cells is then digested with water containing about one per cent. of hydrochloric or other suitable mineral acid, again preferably in oacuo, which dilute acid extracts some of the nitrogenous contents of the yeast-cells and is run off, or it may be treated to recover the dissolved albuminous Serial No. 132,483. (No specimens.)

material. The residue of partlyemptied yeast-cells is then digested again, preferably in cacao, with an alkaline solutioncontain ing about one per cent. of sodium or potassium hydroxid which dissolves further portions of the contents of the yeast-cells not acted upon by the dilute acid.

As the presence of free alkali or albuminous material in an alkaline condition is undesirable for most applications of the product, the residue from the last operation is again treated with dilute mineral acid for a short time and is then washed with water.

The resulting product forms a paste, which may be concentrated at low temperatures to any desired consistence or may be desiccated to dryness.

I wish to'be clearly understood that while the above-described process of treating yeast is suitable for mypurpose, I do not limit myself to the use of a material obtained from untreated yeast. Yeast treated so as to furnish nutritive or other extracts leaves a residue, which by applying the later stages of the process indicated above may be used as a decolorizer, and I expressly contemplate the utilization of such residues for the manufacture of my material for decolorizing purposes. It has the power of removing organic color= ing-matter contained in solutions and may therefore be employed for decolorizing tannin extracts made from barks, woods, leaves, or other parts of plants, for clarifying fermented liquors, and in other cases where a solution containing organic coloring-matters has to be decolorized or clarifie WVhat I claim as my invention, and desire to secure by Letters Patent, is

1. The process of manufacturing a material to be used for decolorizing and clarifying tanning extracts and other liquids, which consists of, first, mixing yeast with water, second,

heating same toabout 50 centigrade and keeping same heated for several hours, third, running off the liquid, fourth, digesting the dead yeast-cells with water containing one per cent. mineral acid, fifth, running off the water, sixth, again digesting the residue with an alkaline solution, seventh, and again treatwashing with water, substantially as set forth.

In witness whereof I have hereunto set my hand in the presence of two witnesses.

R. L. JENKS.

\Vitnesses CLAUDE K. MILLS, \VM.G1RLING. 

